Q&A: North American Code Requirements for Plastic Pipes and Fittings

Most state drinking water regulations and local plumbing codes require PE and PEX tubing and fittings conveying drinking water to meet NSF/ANSI Standard 61 to ensure components will not contribute harmful levels of contaminants to drinking water. All U.S. model plumbing codes and 46 of the 50 U.S. states require PVC drinking water system components to meet the requirements of NSF/ANSI Standard 61.

NSF/ANSI Standard 61: Drinking Water System Components-Health Effects is the American National Standard for health effects of drinking water system components. It establishes the health effects requirements for the chemical contaminants and impurities that are indirectly imparted to drinking water from products, components and materials used in drinking water systems.

NSF/ANSI Standard 61 is overseen by the NSF Drinking Water Additives Joint Committee comprised of representation from the regulatory community, the manufacturing industry and user groups. The American National Standards Institute accredits NSF standards development procedures to ensure a balanced committee of stakeholders develops the standards in an open process. The NSF Council of Public Health Consultants, a group of 30 representatives from academia and local, state and federal regulatory agencies, provides technical advice on and oversight of the NSF standards.

The NSF Health Advisory Board is a standing task group that consists of toxicologists from the U.S. EPA, Health Canada, state and provincial agencies, industry and private consulting firms. This group is responsible for reviewing and approving all allowable contaminant concentrations that are published in NSF/ANSI Standard 61.

NSF/ANSI 14 is used to evaluate a product for minimum performance requirements. NSF conducts its own testing, review and facility inspections when certifying products. If the product is to be used with potable water, it is also evaluated to NSF/ANSI Standard 61 to meet the NSF/ANSI Standard 14 potable water requirements. NSF/ANSI Standard 14 addresses health and performance, NSF/ANSI Standard 61 only addresses health effect concerns.

First, we perform a formulation review of the material to determine what possible contaminants could leach out into drinking water and what type of chemical extraction testing is necessary. Our policy does not allow lead as an ingredient within plastic pipe formulations.

We expose products to formulated exposure waters, and then analyze these exposure waters for contaminants. We use three separate formulated waters during product exposure: pH 5.0 and pH 10.0 (with 2 mg/L available chlorine for PE pipe and fittings) for extraction of metallic contaminants, and pH 8.0 for organic-based contaminants.

Products are conditioned by exposure to the formulated waters (with the addition of 2 mg/L available chlorine for PE products) for 14 days, with water being changed on 10 of those days. We then analyze the water collected from the final 16-hour exposure period for contaminants. Any contaminants found must be below EPA or Health Canada levels for regulated contaminants. For non-regulated contaminants found, NSF/ANSI Standard 61 sets health based pass/fail levels based on review of available toxicity data using the risk assessment procedures in annex A of the standard.

Any other potential contaminant identified during the formulation review

These test methods are capable of detecting contaminants in water as low as 4 parts per billion (4 ppb) and lower, equivalent to a 0.0000004 percent concentration.

PEX tubing and various fittings, either plastic or metal, are tested together as systems for performance and health effects in accordance with industry standards to ensure product quality and end-user safety.

Both the product manufacturer and independent third parties conduct routine quality control and quality assurance evaluations to ensure the product meets ASTM and NSF/ANSI standards. Compliance with ASTM F 876 and F 877 as well as NSF/ANSI Standard 14 ensures the end user of safety and quality.

Plastic pipe, fittings and system components meeting the health effects requirements of NSF/ANSI Standard 61 bear either the NSF-61 mark or the NSF-pw (potable water) mark on the print string. The NSF-pw mark indicates the product meets the health requirements of NSF/ANSI 61 as well as the performance, long-term strength and quality control requirements of NSF/ANSI Standard 14: Plastic Piping Components and Related Materials.

If a PEX product has only an NSF-rfh mark, this indicates the product has only been evaluated for radiant floor heating applications.

If a PVC product has only an NSF-dwv or NSF-sewer mark, the product has only been evaluated for drain, waste and vent applications or for sewer applications, respectively.

PEX is similar to PE that has undergone some additional physical changes. The “X” in PEX stands for crosslinked. This means that PEX has additional links between the polymer chains, which provide additional performance capabilities that ordinary PE does not have. The crosslinking gives PEX tubing high performance capabilities at high operating pressures and temperatures of 160 psi at 73° F, 100 psi at 180° F and 80 psi at 200° F (as noted for SDR 9 tubing in ASTM F876).

PEX tubing was developed in the 1960s in Europe. PEX has been in use in many European countries for decades. In the 1980s, PEX tubing started being used in the United States. Since then, both market demand for and production of PEX has significantly increased in North America.

For products listed for potable water applications, NSF performs at least two unannounced audits of each production facility annually. During the audit, we verify the quality control tests being done by the manufacturer and that there are no modifications to the product formulation and processing. In addition, we collect samples for laboratory retesting of each product family on an annual basis.

If you have questions about the testing and certification of any NSF certified product, contact our Consumer Affairs Hotline at 800.673.8010 or our Regulatory Affairs Hotline at 877.867.3435, or email info@nsf.org.

Founded in 1944, NSF International is committed to protecting and improving human health and the environment on a global scale. NSF International is a global independent organization that provides standards development, product certification, testing, auditing, education and risk management for public health and the environment. Manufacturers, regulators and consumers alike look to NSF International for the development of public health standards and certification that help protect the world’s food, water, health and consumer products.

In 1990, the U.S. EPA replaced its own drinking water product advisory program with NSF standards, including NSF/ANSI 61, for all materials and products that treat or come in contact with drinking water. Today, most plumbing codes require certification to NSF standards for pipes and plumbing components in commercial and residential buildings.

NSF is accredited by ANSI, the American National Standards Institute, and SCC, the Standards Council of Canada, for its testing, standards writing and certification programs. NSF has decades of experience and technical expertise in the areas of water and food safety.

NSF testing and certification are recognized by every plumbing code in North America. No certification mark is more widely recognized and accepted in the plumbing industry. NSF certification is considered the benchmark for product safety and performance validation.

We evaluate products based on end use and adherence to the requirements of standards. Our evaluations routinely include health safety assessment and performance validation of products and materials. Beyond testing, our staff members conduct assessments of the quality control and quality assurance systems employed by the production facility. We register a list of materials and suppliers to manufacturers to maintain consistency and ensure quality. We also conduct unannounced surveillance inspections at the production site to review materials of use, production process and product quality, and to obtain monitoring (re-testing) samples.

ASTM is an independent, not-for-profit standards-writing organization in many diverse technical disciplines. ASTM is the forum for a majority of standards in the USA, especially those related to plastic materials and products testing. ASTM writes standards and conducts educational training seminars (specifications, test methods and guides). ASTM does not conduct testing, listing, certifying or enforcement of its standards.